Acute tuberculosis requires special mention as an undoubted and fatal consequence of measles. Measles, indeed, is followed by true tubercular disease with such frequency that in every case where we are called to a child who has been left weak and feverish after a recent attack of the ex anthematous disorder, we may expect him to be the subject either of catarrhal pneumonia or of acute tuberculosis.
Diaqnoszs.—Before the stage of eruption measles is not easy to detect. A severe cold in the child is often accompanied by fever, and there is nothing in the catarrhal symptoms of measles which can be considered peculiar to that complaint. If such symptoms occur at a time when we know an epidemic to be raging, the probabilities are no doubt strongly in favour of an attack of this disorder ; but in the opposite case, if we cannot ascertain that the child has been exposed to contagion, it is wise to wait before expressing an opinion. Still, we should never forget in any case of high temperature in a child with signs of general catarrh, that these are the early symptoms of measles ; and we should inquire as to the existence of the disease in the neighbourhood.
The presence of the catarrhal phenomena will enable us to exclude scarlatina should the combination of sore throat and high temperature have led us to suspect the onset of that disorder. If laryngitis with stridor and spasm be an early symptom, the persistence of high fever after the spas modic attack is at an end will suggest that these manifestations may be symptomatic of some latent febrile disorder, and we shall remember that measles is sometimes ushered in by laryngeal troubles.
When the rash appears we shall be less liable to fall into error. The crescentic, slightly elevated patches with the skin between them of a healthy tint, combined with coryza and cough, are very characteristic. If the eruption come out first as hardish isolated papules, small-pox may be suspected, and indeed this is a mistake which is often made. But the papules have not the hard shotty feeling peculiar to the variolous erup tion ; there is no history of pain in the back ; and vomiting, if it have oc curred, is much less severe than of the pre-eruptive period of small-pox. Moreover, in variola the temperature falls notably on the ap pearance of the rash ; while in measles, if any change occur at all in the fever, it is in the opposite direction ; and the catarrhal symptoms become aggravated. Doubt is only permissible at the very beginning of the erup
tive stage ; for on the second day the rash of small-pox has completely changed its character on the face of the patient, the papules having become converted into vesicles.
The rash of roseola may bear a close resemblance to that of measles, but in the former complaint there is no catarrh, and the temperature is normal or only slightly elevated. Between epidemic roseola (or rotheln) and measles the difficulty of distinguishing is often very great. This sub ject is referred to in the chapter treating of the former disorder (see page 30). I have also known the early signs on the skin of an acute gen eral eczema to present the closest possible resemblance to measles. But an exanthem should never be judged of by the rash alone. In every case we should search for confirmatory symptoms, and inquire as to the tem perature and the initiatory phenomena of the illness. In measles we ex amine the eyes for injection, the throat for redness, and ask about cough, hoarseness, and catarrhal symptoms generally. If these are completely ab sent, and the temperature be below 100°, it is very unlikely that the disease is measles, however typical the rash may appear.
The stains left on the skin as the rubeolous eruption dies away have been compared to the mottling of syphilitic roseola, but the history and course of the illness are so different in the two cases that hesitation is im possible.
Prognosis.—The percentage of mortality in measles is small. Still, it is much higher in some epidemics than it is in others ; and, therefore, in estimating the chances of a patient's recovery we must take into account the character of the epidemic. Another consideration is the previous state of health, especially the constitutional tendencies of the child. Unless the case be one of malignant measles, or the child have been pre viously in a state of great weakness, there is every hope of preserving life if ordinary care be exercised in nursing the patient through his ill ness. But it is less easy to avert injury to the health from the dangerous sequelae of the disease. In spite of all we can do, a child of strong scrof ulous predisposition may be left greatly the worse for the attack ; and if his lungs be already the seat of caseous consolidation, it will be difficult indeed to prevent his phthisical tendencies from receiving a distinct impulse.